RRAM cell structure with laterally offset BEVA/TEVA

ABSTRACT

The present disclosure relates to a resistive random access memory (RRAM) device. The RRAM device has a bottom electrode arranged over a bottom electrode via. A variable resistive dielectric layer is arranged over the bottom electrode. The variable resistive dielectric layer extends to within a recess in an upper surface of the bottom electrode. A top electrode is disposed over the variable resistive dielectric layer. A top electrode via extends outward from an upper surface of the top electrode at a position centered along a first axis that is laterally offset from a second axis centered upon the recess within the upper surface of the bottom electrode. The top electrode via has a smaller total width than the top electrode.

REFERENCE TO RELATED APPLICATION

This Application is a Continuation of U.S. application Ser. No.14/803,377 filed on Jul. 20, 2015, which is a Divisional of U.S.application Ser. No. 14/041,514 filed on Sep. 30, 2013 (now U.S. Pat.No. 9,112,148 issued on Aug. 18, 2015), the contents of which areincorporated by reference in their entirety.

BACKGROUND

Non-volatile memories are used in a wide variety of commercial andmilitary electronic devices and equipment. Embedded flash memory devicesare used to store data and executable programs in integrated chips. Asthe functionality of an integrated chip increases, the need for morememory also increases, causing integrated chip designers andmanufacturers to have to both increase the amount of available memorywhile decreasing the size and power consumption of an integrated chip.To reach this goal, the size of memory cell components has beenaggressively shrunk over the past few decades. As the process technologymigrates to smaller cell sizes, the integration of floating gate withhigh-k metal gate becomes complicated and expensive for embedded flashmemory. Resistive random access memory (RRAM) is one promising candidatefor next generation non-volatile memory technology due to its simplestructure and CMOS logic compatible process technology that is involved.

The RRAM cell is a metal oxide material sandwiched between top andbottom electrodes. However, traditional RRAM cells can cause highcontact resistance variations at the top electrode via. The currentdisclosure aims at lowering the contact resistance variation, loweringforming voltage and improving data retention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates a top view of some embodiments of a resistive randomaccess memory (RRAM) device according to the present disclosure.

FIG. 1B illustrates a cross sectional view of one of the RRAM cells ofthe RRAM device in FIG. 1 according to some embodiments of the presentdisclosure.

FIG. 2 illustrates a flow diagram of some embodiments of a method forforming an RRAM device according to the present disclosure.

FIG. 3 illustrates a flow diagram of some embodiments of a method forforming a top electrode via on an RRAM cell according to the presentdisclosure.

FIG. 4 illustrates a cross sectional view of some embodiments of alaterally offset top electrode via (TEVA) and bottom electrode via(BEVA) on a memory cell, according to the present disclosure.

FIGS. 5A-5D illustrate some embodiments of laterally offset and notlaterally offset structures according to the present disclosure.

FIG. 6 illustrates a cross sectional view of some embodiments of an RRAMdevice with a laterally offset TEVA and BEVA according to the presentdisclosure.

FIGS. 7A-7F illustrate embodiments of cross sectional images of a methodof formation of a TEVA according to the present disclosure.

FIG. 8 illustrates a cross sectional view of some embodiments of an RRAMdevice with a laterally offset TEVA and BEVA with no insulating materialabutting the top electrode.

DETAILED DESCRIPTION

The description herein is made with reference to the drawings, whereinlike reference numerals are generally utilized to refer to like elementsthroughout, and wherein the various structures are not necessarily drawnto scale. In the following description, for purposes of explanation,numerous specific details are set forth in order to facilitateunderstanding. It may be evident, however, to one skilled in the art,that one or more aspects described herein may be practiced with a lesserdegree of these specific details. In other instances, known structuresand devices are shown in block diagram form to facilitate understanding.

A RRAM cell includes two electrodes with a resistive switching elementplaced between the two electrodes. Resistive switching elements or avariable resistive dielectric layer use a “forming process” to prepare amemory device for use. The forming process is typically applied at thefactory, at assembly, or at initial system configuration. A resistiveswitching material is normally insulating, but a sufficient voltage(known as a forming voltage) applied to the resistive switching materialwill form one or more conductive pathways in the resistive switchingmaterial. Through the appropriate application of various voltages (e.g.a set voltage and reset voltage), the conductive pathways may bemodified to form a high resistance state or a low resistance state. Forexample, a resistive switching material may change from a firstresistivity to a second resistivity upon the application of a setvoltage, and from the second resistivity back to the first resistivityupon the application of a reset voltage.

A RRAM cell may be regarded as storing a logical bit, where theresistive switching element has increased resistance, the RRAM cell maybe regarded as storing a “0” bit; where the resistive switching elementhas reduced resistance, the RRAM cell may be regarded as storing a “1”bit, and vice-versa. A circuitry may be used to read the resistive stateof the resistive switching element by applying a read voltage to the twoelectrodes and measuring the corresponding current through the resistiveswitching element. If the current through the resistive switchingelement is greater than some predetermined baseline current, theresistive switching element is deemed to be in a reduced resistancestate, and therefore the RRAM cell is storing a logical “1.” On theother hand, if the current through the resistive switching element isless than some predetermined baseline current, then the resistiveswitching element is deemed to be in an increased resistance state, andtherefore the RRAM cell is storing a logical “0.”

RRAM cells have conductive interconnects comprising a top electrode via(TEVA) and a bottom electrode via (BEVA) that connects the top andbottom electrodes to the rest of the device. In traditional RRAM cells,they are located along a same vertical axis. In such cases, ananti-reflective layer that may remain above the top electrode wouldcause high contact resistance on the TEVA if the TEVA is placed at thatlocation.

Accordingly, the present disclosure relates to a new architecture forRRAM cells that can improve the contact resistance variation at the topelectrode via. In some embodiments, conductive interconnects, comprisingthe TEVA and the BEVA are laterally offset, so that the TEVA is awayfrom the insulating antireflective layer which can reduce the contactresistance variations. Furthermore, the shape and dimensions of the RRAMcell is chosen in such a way that it accommodates the conductiveinterconnects at both ends within an area of the RRAM cell. A small cellsize and high density memory may bring adverse effects to associatedlogic circuitry like stress around RRAM area for abnormal dopantdiffusion and junction leakage, lower yield, reliability concerns, etc.This can cause an increase in the forming voltage. The larger area wouldhelp reduce the forming voltage and also improve the data retention ofthe memory device.

FIG. 1A illustrates a top view of a memory device 100 a in accordancewith some embodiments that includes a number of memory cells arranged ina series of columns and rows. Memory array 101 comprises a plurality ofmemory cells configured to store data. For purposes of illustration,FIG. 1A's memory cells are arranged in two rows and two columns whereinthe individual cells are labeled C_(row-column), although typicalembodiments will include thousands, millions or other numbers of rowsand columns that collectively establish a memory array to store digitaldata. Memory cell C22 comprises an RRAM cell 102 that is sandwichedbetween a top electrode via 104 and a bottom electrode via 106. Thebottom electrode via 106 is in contact with a first metal contactassociated with an area 108. The semiconductor substrate over which thememory cell is disposed is illustrated by reference numeral 110.

FIG. 1B illustrates the cross sectional image of the memory cell C21along a length of the RRAM cell of the memory cell C21. The RRAM cellresides over a semiconductor area 108 comprising a conductive region 108a such as metal which has extremely low-k dielectric region 108 b oneither side. Right above the semiconductor area 108 resides a dielectricprotection layer 112 having an open region above the metal region 108 a,wherein sidewalls of dielectric protection layer 112 culminate withrounded ends above the metal 108 a. The dielectric protection layer 112protects the semiconductor area 108 from future etching steps. In oneembodiment, a bottom electrode via (BEVA) 106 resides over a definedregion above the dielectric protection layer, follows the shape of therounded ends of the dielectric protection layer 112 in a dipping fashionand resides over the open region contacting the metal 108 a in thesemiconductor area 108. A bottom electrode (BE) 114 resides above theBEVA, abutting the top surface of the BEVA. A variable resistivedielectric layer or resistive switching element 116 resides abutting theentire surface of the BE. A top electrode (TE) 118 resides above thevariable resistive dielectric layer 118 at a defined region. In oneembodiment the top electrode 118 comprises a first TE layer 118 a and asecond TE layer 118 b that resides on top of first TE 118 a. Two spacers120 a and 120 b are disposed on either side of the TE 118. The spacers120 a and 120 b also reside on the two end locations of the variableresistive dielectric layer 116. A top electrode via (TEVA) is located atone side of the second TE layer 118 b. This location makes the TEVAlaterally offset from the BEVA/metal interface or the conductiveinterconnect that connects the bottom of the RRAM cell with the rest ofthe device. An antireflective layer 122 is disposed above the second TElayer 118 b at a location different from the TEVA location. Theantireflective layer 122 is situated vertically above the metal region108 a, in an indention above the TE layer 118 b and resides in suchlocation incidentally due to manufacturing process, as will be moreappreciated later in the disclosure.

FIG. 2 illustrates a flow diagram of some embodiments of a method 200for forming an RRAM device with laterally offset BEVA and TEVA accordingto the present disclosure.

While disclosed method 200 is illustrated and described below as aseries of acts or events, it will be appreciated that the illustratedordering of such acts or events are not to be interpreted in a limitingsense. For example, some acts may occur in different orders and/orconcurrently with other acts or events apart from those illustratedand/or described herein. In addition, not all illustrated acts may berequired to implement one or more aspects or embodiments of thedescription herein. Further, one or more of the acts depicted herein maybe carried out in one or more separate acts and/or phases.

At 202, a first conductive interconnect is formed abutting a firstsurface of an RRAM cell at a first location.

At 204, a second conductive interconnect is formed abutting a second,different surface of the RRAM cell at a second location such that, thefirst and second locations are laterally offset from one another. In oneembodiment, the first surface is a bottom surface of the RRAM cell whilethe second surface is a top surface of the RRAM cell.

FIG. 3 illustrates a flow diagram of some embodiments of a method 300for forming a top electrode via (TEVA) on an RRAM cell according to thepresent disclosure.

While disclosed method 300 is illustrated and described below as aseries of acts or events, it will be appreciated that the illustratedordering of such acts or events are not to be interpreted in a limitingsense. For example, some acts may occur in different orders and/orconcurrently with other acts or events apart from those illustratedand/or described herein. In addition, not all illustrated acts may berequired to implement one or more aspects or embodiments of thedescription herein. Further, one or more of the acts depicted herein maybe carried out in one or more separate acts and/or phases.

At 302, an antireflective/insulating layer is deposited over the topelectrode of the RRAM cell. This antireflective layer protects the RRAMsurface from future photo-patterning and etching steps that may takeplace over the RRAM cell. In some embodiments, the antireflective layerdeposited over the TE comprises silicon oxy-nitride (SiON).

At 304, a photolithographic step that includes an anisotropic etch iscarried out to pattern and etch the top electrode leaving the variableresistive dielectric layer open or otherwise exposed at two endlocations. In some embodiments, the photolithographic step does notcompletely remove the antireflective layer at a location that overliesthe top electrode and some of it is left at a center location verticallyabove the metal region that forms the bottom contact associated with theBEVA. In some embodiments, the antireflective layer is completelyremoved in the etching step.

At 306, a spacer material is deposited all over the semiconductor bodyto form a single layer over the entire RRAM cell. In some embodiments,the spacer material comprises silicon nitride (SiN).

At 308, the spacer material is etched to form spacers on both ends ofthe top electrode. The spacers reside on the open, exposed end locationsof the variable resistive dielectric layer.

At 310, another photolithographic step is carried out that etches thebottom electrode at defined regions, leaving the protective dielectriclayer open at its two end locations.

At 312, a top electrode via (TEVA) is formed abutting the top electrodeat a location that is laterally disposed away from the center location.This will make sure the TEVA is not in contact with the insulatingantireflective layer and thus there is no increase in contact resistanceunlike conventional arrangements. The TEVA is also laterally offset fromthe conductive interconnect that connects the bottom of the RRAM cell tothe rest of the device.

FIG. 4 illustrates a cross sectional view of some embodiments of a RRAMdevice 400 which has an overlying conductive interconnect and anunderlying conductive interconnect that are laterally offset from oneanother, according to the present disclosure. An RRAM cell 402 issandwiched between two conductive interconnects that are laterallyoffset. Reference numeral 404 represents the overlying conductiveinterconnect that abuts the top surface 402 a of the RRAM cell 402 andreference number 406 represents the underlying conductive interconnectthat abuts the bottom surface 402 b of the RRAM cell 402. Thehighlighted dotted region on the top surface 402 a represents a firstlocation 403 a at which the overlying conductive interconnect isdisposed and the highlighted dotted region 403 b on the bottom surface402 b represents a second location 403 b at which the underlyingconductive interconnect is disposed. The first location 403 a and thesecond location 403 b are laterally offset from one another. The conceptof lateral offsetting is explained in detail in the following figures.

FIGS. 5A-5D illustrate some embodiments of laterally offset and notlaterally offset objects. In order to explain laterally offsetting twoobjects, two axes that are perpendicular to a horizontal plane and thatpass through the centers of two objects are introduced. If the axes areseparated by a non-zero distance, then the two objects are said to belaterally offset or off-axis.

FIG. 5A illustrates an arrangement 500 a of two laterally offset objects504 and 506 along a horizontal or lateral axis 502. 508 is a first axisthat passes through the center of object 504 and 510 is a second axisthat passes through the center of object 506. A non-zero distance whichis observed between the two axes is represented by the reference numeral512. Here, even though the objects are seen to be overlapping at adistance along the horizontal axis 502, the distance between the axes512 shows that objects 504 and 508 are laterally offset or off-axis withrespect to one another.

FIG. 5B represents an arrangement 500 b of another embodiment oflaterally offset objects. In this case, the corners of objects 504 and506 touch at a single point along the lateral axis 502. However, thereis a non-zero distance 512 between the perpendicular axes 508 and 510and hence the objects 504 and 506 are laterally offset or off-axis withrespect to one another.

FIG. 5C shows another yet embodiment of laterally offset objects in anarrangement 500 c. Here the objects 504 and 506 have no connectingregion along the horizontal axis 502. Hence there is a very distinctnon-zero distance between the axes 508 and 510 and the objects arelaterally offset or off-axis with respect to one another.

FIG. 5D represents an arrangement 500 d that illustrates an embodimentwhere two objects are not laterally offset or on-axis. No distance isobserved between the two axes 508 and 510 or the two axes coincide withone another which makes the two objects 504 and 506 on-axis or notlaterally offset with respect to one another.

FIG. 6 illustrates a cross sectional view of some embodiments of an RRAMdevice 600 with a laterally offset TEVA and BEVA according to thepresent disclosure. A plurality of such RRAM devices form a memory arrayconfigured to store data. In one embodiment a selection transistor isassociated with each RRAM device. The selection transistor is configuredto suppress sneak-path leakage (i.e., prevent current intended for aparticular memory cell from passing through an adjacent memory cell)while providing enough driving current for memory cell operation. FIG. 6comprises a conventional planar MOSFET selection transistor 601. Theselection transistor 601 comprises a source 604 and a drain 606comprised within a semiconductor body 602, separated horizontally by achannel region 605. A gate electrode 608 is located on the semiconductorbody 602 at a position that is above the channel region 605. In someembodiments, the gate electrode comprises poly silicon. The gateelectrode 608 is separated from the source 604 and drain 606 by a gateoxide layer or gate dielectric layer 607 extending laterally over thesurface of the semiconductor body 602. The drain 606 is connected to adata storage element or RRAM cell 620 by way of a first metal contact612 a. The source 604 is connected by way of a second metal contact 612b. The gate electrode is connected to a word line 614 a, the source isconnected to a select line 614 b through the second metal contact 612 band the RRAM cell 620 is further connected to a bit line 614 c comprisedwithin an upper metallization layer by way of an additional metalcontact 612 g. A desired RRAM device may be selectively accessed usingword lines and bit lines for reading, writing and erasing operations.One or more metal contacts comprising 612 c, 612 d, 612 e, 612 f andmetal contact vias comprising 610 a, 610 b, 610 c, 610 d, 610 e, 610 fetc. that helps in connecting the RRAM memory device with the externalcircuitry may be present between the drain and the first metal contact,and between the source and the second metal contact. In someembodiments, the metal contacts comprise copper (Cu).

The RRAM cell 620 comprises a resistive switching element/variableresistive dielectric layer 621 sandwiched between a top electrode 622and a bottom electrode 623. In some embodiments, the top electrodecomprises titanium (Ti) and tantalum nitride (TaN), the bottom electrodecomprises titanium nitride (TiN), and the resistive switching elementcomprises hafnium dioxide (HfO2). A top electrode via (TEVA) 624connects the top electrode 622 of the memory cell 620 to the uppermetallization layer 612 g and a bottom electrode via (BEVA) 625 connectsthe bottom electrode 623 of the RRAM cell 620 to the first metalcontact/lower metallization layer 612 a. The TEVA 624 and the BEVA 625are positioned in a laterally offset manner with respect to one anotherin order to lower the contact resistance that may build up between theTEVA 624 and the underlying insulator layer (not shown), that resides ina central location above the top electrode 622. The RRAM cell 620 alsohas an enlarged generally rectangular or elongated area so as toaccommodate the laterally offset TEVA and BEVA. The larger elongatedarea can lower the forming voltage and also improve data retention inthe RRAM cell.

FIGS. 7A-7F show cross sectional images of various embodiments ofcorresponding method 300 wherein a top electrode via (TEVA) is formedaccording to the present disclosure.

FIG. 7A shows a cross-sectional image of an embodiment of asemiconductor body 700 a that comprises an RRAM cell, a BEVA and anunderlying metal interconnect. The semiconductor body 700 a comprises asemiconductor area 702 comprising a conductive metal region 703 disposedwithin an insulating layer such as an extremely low-k dielectric layer704. In some embodiments, the metal region comprises copper (Cu) and theextremely low-k dielectric layer comprises porous silicon dioxide,fluorinated silica glass, polyimides, polynorbornenes, benzocyclobutene,or PTFE. A dielectric protection layer 706 having an open region abovethe metal, wherein sidewalls of dielectric protection layer end withrounded ends above the metal due to etching, is disposed above thesemiconductor area 702. In some embodiments, the dielectric protectionlayer comprises silicon carbide (SiC). A bottom electrode via (BEVA) 708resides conformally over a defined region above the dielectricprotection layer 706. It follows the shape of the rounded ends of thedielectric protection layer in a dipping fashion and also resides overthe open region contacting the metal 703 in the semiconductor area 702.In some embodiments, the BEVA comprises tantalum nitride (TaN). A bottomelectrode (BE) 710 resides entirely over the BEVA, and above the BEresides a variable resistive dielectric layer 712. The variableresistive dielectric layer is normally insulating, but a sufficientvoltage applied to the variable resistive dielectric material will formone or more conductive pathways in the variable resistive dielectric.Through the appropriate application of various voltages (e.g. a setvoltage and reset voltage), the conductive pathways may be modified toform a high resistance state or a low resistance state. In someembodiments, the BE 710 comprises titanium nitride (TiN) and thevariable resistive dielectric layer comprises hafnium dioxide (HfO2). Ontop of the variable resistive dielectric layer 712 resides a first topelectrode layer 714 and abutting that layer, a second top electrodelayer 716 is disposed. In some embodiments the first top electrode layercomprises titanium (Ti) and the second top electrode layer comprisesTaN. Abutting the entire second top electrode layer 716, an insulatinganti-reflective layer 718 is deposited. This layer protects theunderlying layers from the future etching steps and operated to improvepatterning by reducing light reflection that causes standing waves. Insome embodiment, the anti-reflective layer comprises SiON.

FIG. 7B shows an embodiment of a semiconductor body 700 b after photopatterning and etching the top electrode (TE). In some embodiments, ananisotropic etching step is carried out, creating open, exposed ends 713for the variable resistive dielectric layer at two end locations. In oneembodiment, the photolithographic step does not completely remove theantireflective layer 718 from the second top electrode layer 716 andsome of it is left at a center location vertically above the metalregion. In another embodiment, the antireflective layer is completelyremoved in the etching step.

FIG. 7C shows an embodiment of a semiconductor body 700 c after a spacermaterial is deposited all over the semiconductor body to form a spacerlayer 720 entirely over the semiconductor body. In some embodiments, thespacer material comprises silicon nitride (SiN).

FIG. 7D shows an embodiment of a semiconductor body 700 d after thespacer layer 720 is etched to form spacers 720 a and 720 b on both endsof the top electrode. The spacers 720 a and 720 b reside on the open endlocations of the variable resistive dielectric layer.

FIG. 7E shows an embodiment of a semiconductor body 700 e after anotherphotolithographic step is carried out that etches the bottom electrode710 and the variable resistive dielectric layer 712 at defined regions.This etching step will leave the protective dielectric layer open at itstwo end locations.

FIG. 7F shows an embodiment of a semiconductor body 700 f after theformation of a top electrode via (TEVA) 722 at a location away from thedipping region. This will make sure the TEVA is not in contact with theinsulating antireflective layer 718 and thus this construction improvesthe contact resistance variation significantly when compared withconventional designs. Thus the TEVA is laterally offset from theconductive interconnect that connects the bottom of the RRAM cell to therest of the device.

FIG. 8 shows an embodiment of an RRAM device 800 having laterally offsetTEVA and BEVA according to the present disclosure, as well as a topelectrode surface that has no insulating anti-reflective layer. In thiscase, the anti-reflective layer is completely removed during step 304 ofmethod 300.

It will be appreciated that while reference is made throughout thisdocument to exemplary structures in discussing aspects of methodologiesdescribed herein that those methodologies are not to be limited by thecorresponding structures presented. Rather, the methodologies (andstructures) are to be considered independent of one another and able tostand alone and be practiced without regard to any of the particularaspects depicted in the FIGS. Additionally, layers described herein, canbe formed in any suitable manner, such as with spin on, sputtering,growth and/or deposition techniques, etc.

Also, equivalent alterations and/or modifications may occur to thoseskilled in the art based upon a reading and/or understanding of thespecification and annexed drawings. The disclosure herein includes allsuch modifications and alterations and is generally not intended to belimited thereby. For example, although the figures provided herein, areillustrated and described to have a particular doping type, it will beappreciated that alternative doping types may be utilized as will beappreciated by one of ordinary skill in the art.

In addition, while a particular feature or aspect may have beendisclosed with respect to only one of several implementations, suchfeature or aspect may be combined with one or more other features and/oraspects of other implementations as may be desired. Furthermore, to theextent that the terms “includes”, “having”, “has”, “with”, and/orvariants thereof are used herein, such terms are intended to beinclusive in meaning—like “comprising.” Also, “exemplary” is merelymeant to mean an example, rather than the best. It is also to beappreciated that features, layers and/or elements depicted herein areillustrated with particular dimensions and/or orientations relative toone another for purposes of simplicity and ease of understanding, andthat the actual dimensions and/or orientations may differ substantiallyfrom that illustrated herein.

The present disclosure relates to resistive random access memory (RRAM)device comprising a resistive random-access memory (RRAM) cell having afirst surface and a second surface, a first conductive interconnectabutting the first surface at a first location and, a second conductiveinterconnect abutting the second surface at a second location, whereinthe first and second locations are laterally offset.

In some embodiments, the present disclosure relates to a resistiverandom access memory (RRAM) device. The RRAM device comprises a bottomelectrode arranged over a bottom electrode via, and a variable resistivedielectric layer arranged over the bottom electrode. The variableresistive dielectric layer extends to within a recess in an uppersurface of the bottom electrode. A top electrode is disposed over thevariable resistive dielectric layer. A top electrode via extends outwardfrom an upper surface of the top electrode at a position centered alonga first axis that is laterally offset from a second axis centered uponthe recess within the upper surface of the bottom electrode. The topelectrode via has a smaller total width than the top electrode.

In another embodiment, the present disclosure relates to a resistiverandom access memory (RRAM) device. The RRAM device comprises a bottomelectrode arranged over a bottom electrode via. The bottom electrodecomprises a recess overlying an opening in an underlying dielectricprotection layer. A variable resistive dielectric layer is arranged overthe bottom electrode, and a top electrode is arranged over the variableresistive dielectric layer. A top electrode via, having a smaller widththan the top electrode, vertically extends outward from an upper surfaceof the top electrode at a position laterally offset from the recess.

In yet another embodiment, the present disclosure relates to a resistiverandom access memory (RRAM) device. The RRAM device comprises aconductive bottom electrode having an upper surface comprising a recess.A variable resistive dielectric layer is arranged over the conductivebottom electrode, and a conductive top electrode is arranged over thevariable resistive dielectric layer. A top electrode via, having asmaller width than the conductive top electrode, vertically extendsoutward from an upper surface of the conductive top electrode at aposition laterally offset from the recess.

What is claimed is:
 1. A resistive random access memory (RRAM) device,comprising: a metal region laterally surrounded by an inter-leveldielectric (ILD) layer; a bottom electrode via having interior sidewallscoupled between upper surfaces and a first recessed surface between theupper surfaces and a bottom surface of the bottom electrode via; abottom electrode arranged over and in contact with the interiorsidewalls of the bottom electrode via; a variable resistive dielectriclayer arranged over the bottom electrode; a top electrode disposed overthe variable resistive dielectric layer; a top electrode via extendingoutward from an upper surface of the top electrode at a positioncentered along a first axis that is laterally offset from a second axiscentered upon the first recessed surface, wherein the top electrode viahas a smaller total width than the top electrode; and wherein the topelectrode has a first non-zero total thickness along outermost sidewallsof the top electrode and a second non-zero total thickness at a locationdirectly over the first recessed surface, the second non-zero totalthickness less than the first non-zero total thickness.
 2. The RRAMdevice of claim 1, further comprising: a dielectric protection layerarranged over the ILD layer and having an uppermost surface that isbelow the bottom electrode via, wherein the dielectric protection layerhas an opening that intersects the second axis.
 3. The RRAM device ofclaim 1, wherein the bottom electrode via has a first total width andthe bottom electrode has a second total width that is substantiallyequal to the first total width.
 4. The RRAM device of claim 1, whereinthe first axis is parallel to the second axis.
 5. The RRAM device ofclaim 1, wherein the top electrode has outermost sidewalls that arelaterally set back from outermost sidewalls of the bottom electrode. 6.The RRAM device of claim 1, wherein the top electrode has outermostsidewalls that are laterally set back from outermost sidewalls of thevariable resistive dielectric layer.
 7. The RRAM device of claim 1,wherein the top electrode and the bottom electrode comprise one or moreof: titanium or tantalum.
 8. The RRAM device of claim 1, wherein thevariable resistive dielectric layer laterally contacts the bottomelectrode.
 9. A resistive random access memory (RRAM) device,comprising: a bottom electrode arranged over a bottom electrode via,wherein the bottom electrode has interior sidewalls and a first recessedsurface overlying an opening in an underlying dielectric protectionlayer, wherein the dielectric protection layer has a first totalthickness below the bottom electrode and a second total thicknesslaterally outside of the bottom electrode that is less than the firsttotal thickness; a variable resistive dielectric layer arranged over thebottom electrode; a top electrode arranged over the variable resistivedielectric layer; and a top electrode via having a smaller width thanthe top electrode and vertically extending outward from an upper surfaceof the top electrode at a position laterally offset from the firstrecessed surface.
 10. The RRAM device of claim 9, further comprising:sidewall spacers arranged along opposing sides of the top electrode,wherein the sidewall spacers are directly over the bottom electrode andare confined above the bottom electrode.
 11. The RRAM device of claim 9,wherein the top electrode and the bottom electrode comprise one or moreof: titanium or tantalum.
 12. The RRAM device of claim 9, wherein aninterior sidewall of the variable resistive dielectric layer laterallyabuts one of the interior sidewalls of the bottom electrode.
 13. TheRRAM device of claim 9, wherein the top electrode has outermostsidewalls that are laterally set back from outermost sidewalls of thebottom electrode.
 14. The RRAM device of claim 9, wherein the topelectrode comprises: a first top electrode layer comprising a firstmaterial; and a second top electrode layer arranged on the first topelectrode layer, wherein the second top electrode layer comprises asecond material that is different than the first material.
 15. Aresistive random access memory (RRAM) device, comprising: a metalstructure laterally surrounded by a dielectric region; a conductivebottom electrode via disposed over the metal structure and laterallyextending past opposing outermost sidewalls of the metal structure,wherein the conductive bottom electrode via has interior sidewallscoupled between upper surfaces and a first recessed surface facing asame direction; a conductive bottom electrode contacting the interiorsidewalls of the conductive bottom electrode via, wherein the conductivebottom electrode has interior sidewalls coupled to a second recessedupper surface disposed directly over the first recessed surface andfacing away from the conductive bottom electrode via; a variableresistive dielectric layer arranged over the conductive bottomelectrode; a conductive top electrode arranged over the variableresistive dielectric layer; and a top electrode via having a smallerwidth than the conductive top electrode and vertically extending outwardfrom an upper surface of the conductive top electrode at a positionlaterally offset from the second recessed upper surface.
 16. The RRAMdevice of claim 15, wherein the conductive top electrode and theconductive bottom electrode comprise a metal.
 17. The RRAM device ofclaim 15, wherein the conductive bottom electrode via has a first totalwidth and the conductive bottom electrode has a second total width thatis substantially equal to the first total width.
 18. The RRAM device ofclaim 15, wherein the conductive top electrode has a first non-zerototal thickness along outermost sidewalls of the conductive topelectrode and a second non-zero total thickness at a location overlyingthe second recessed upper surface; and wherein the second non-zero totalthickness is less than the first total non-zero thickness.
 19. The RRAMdevice of claim 15, wherein an interior sidewall of the variableresistive dielectric layer faces one of the interior sidewalls of theconductive bottom electrode.
 20. The RRAM device of claim 15, furthercomprising: sidewall spacers arranged along opposing sides of theconductive top electrode, wherein the sidewall spacers are directly overthe conductive bottom electrode.